The field of art to which this invention pertains is the production of a hydrogenated distillable hydrocarbonaceous product from a temperature-sensitive hydrocarbonaceous stream containing a non-distillable component. More specifically, the invention relates to a process for treating a temperature-sensitive hydrocarbonaceous stream containing a non-distillable component and a distillable, hydrogenatable hydrocarbonaceous fraction to produce a selected hydrogenated distillable light hydrocarbonaceous product, a distillable heavy hydrocarbonaceous liquid product, and a heavy product comprising the non-distillable component while minimizing thermal degradation of the temperature-sensitive hydrocarbonaceous stream which process comprises the steps of: (a) contacting the temperature-sensitive hydrocarbonaceous stream with a hot first hydrogen-rich gaseous stream having a temperature greater than the hydrocarbonaceous stream in a flash zone at flash conditions thereby increasing the temperature of the hydrocarbonaceous stream and vaporizing at least a portion thereof to provide a first hydrocarbonaceous vapor stream comprising hydrogen and a first heavy product stream comprising the non-distillable component; (b) condensing at least a portion of the first hydrocarbonaceous vapor stream to provide a distillable heavy hadrocarbonaceous liquid stream and a second hydrocarbonaceous vapor stream comprising hydrogen and the hydrogenatable, hydrocarbonaceous fraction; (c) contacting the second hydrocarbonaceous vapor stream comprising hydrogen from step (b) with a hydrogenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrogenatable hydrocarbonaceous fraction introduced into the hydrogenation reaction zone; (d) condensing at least a portion of the resulting effluent from the hydrogenation zone to provide a second hydrogen-rich gaseous stream and a liquid stream comprising hydrogenated distillable hydrocarbonaceous compounds; and (e) recovering the selected hydrogenated distillable light hydrocarbonaceous product from the liquid stream comprising hydrogenated distillable hydrocarbonaceous compounds.